How to Save a Life
by GhostWriter030791
Summary: While playing Eurus's games in "The Final Problem", John is killed. Sherlock locks himself away and falls back into bad habits without his blogger. Eighteen years later, Rosie Watson shows up on his doorstep. Turns out her father has no intention of death keeping him from looking after his best friend, whether Sherlock likes it or not.
1. Chapter 1

1)

 _My dearest Rosie,_

 _Today is your eighteenth birthday, and I hope to God you aren't reading this. If you are, it means I'm not there to celebrate with you. It means I'm dead._

 _Sorry for the cliché._

 _I want you to know, that no matter the circumstances of my death, I loved you more than life itself. You were the most important person in the world to me, and I was so incredibly lucky to have been your father._

 _I'm hoping this never reaches you, but if it does I hope you have your mother's smile and determination. I hope you're stubborn and set in your ways like me. I hope you don't put up with shit like your godmother Molly, you are generous with your love like your godmother Martha, and I hope you are a loyal and kind friend like your uncle Greg._

 _I have a job for you, and you are going to need determination, stubbornness, loyalty, kindness, and the ability to see through someone's bullshit._

 _Together you and I are going to save your godfather's life, whether he likes it or not. I don't know what kind of shape he's in, or for how long he's been that way, but if I'm not there, I promise he will have spiraled down a path of self-destruction even he thinks he won't be able to crawl out of. There will have been attempts before to save him, and he will have brushed them off before._

 _You are going to have to show him that Watsons are made of sterner stuff than even his older brother._

 _I'm warning you now, this is not an easy job I have unfortunately been forced to give you. Your godfather is the most unpleasant, rude, ignorant, and all around obnoxious arsehole that anyone could possibly have the misfortune to meet. He will voluntarily and openly explain to anyone that questions him that all emotions stand opposed to the pure cold reason he holds above all else. He will openly admit, even to people who don't ask, that he is a high-functioning sociopath._

 _If he is behaving in the way that I suspect he will be if something happens to me, those spectacular qualities of his are going to be magnified. He will have isolated himself and will probably be abusing drugs. No matter the situation, rest assured, he will not be a danger to_ you.

 _Keep a close eye on any civilians you bring into contact with him though. I cannot promise his self-control will extend to innocent bystanders._

 _If you know him already, then you know who and what you are up against. If you don't, then the situation is worse than I thought, and I'm sorry for putting you through this. However, I promise you are the only one who can save him. You're the only one he will listen and respond to. It's a cross us Watsons have to bear and now that privilege belongs to you._

 _I'm going to assume that you don't know what you're walking into, so I suppose we should start at the beginning._

 _His name is Sherlock Holmes, and the address is 221B Baker Street._

* * *

Sherlock groaned, covering his eyes against the dim light that flooded his flat. The pounding noise he had originally attributed to ambient noise in his mind palace suddenly registered as a tangible force. Sherlock squinted suspiciously at the door from his prone position on the couch; the whole of London knew he didn't take cases anymore. He couldn't even recall the last time Mrs. Hudson had visited.

Mycroft was the only person who could be counted upon to continue to try to impose his presence on Sherlock, and even then, he usually just let himself in, standing disapprovingly in the doorway until Sherlock drove him away.

The pounding on his door stopped for a long moment, and Sherlock could swear he heard annoyed murmuring on the other side. Then it took up again, if possible, louder than before.

Something that felt vaguely like curiosity tickled the back of his mind and before he'd had time to consider the action he was rolling off the couch, stepping over the coffee table, and wrenching the door open with a scowl he hoped would send even the most determined solicitor running for cover.

Standing on the other side of the door was not, in fact, a salesperson or his brother, but John Watson, looking the same as he had when he'd died. Sherlock had hallucinated John before, did so on a regular basis in fact, but the hallucinations had never been so loud and persistent in their quest for his attention.

They'd also never shown up at his doorway, shoved past him, or began looking around his flat disapprovingly before.

Sherlock dazedly shut the door and turned to face the intruder into his flat. His vision swam as he looked at it, and when be blinked the haziness away, he realized it wasn't John at all, but a young woman wearing jeans, converse, and a light brown long sleeved top. Her blonde hair was pinned up in a messy bun on top of her head, and when she turned around to look at him silver dog tags hung around her neck.

When Sherlock met her gaze with his own, the eyes staring back at him were familiar, and he knew exactly who was standing among the startled dust motes in the middle of the sitting area of his flat.

"Rosie." he said, voice rasping against his throat.

"Good deduction," she said, voice displaying her disapproval even more. Underneath it though, was something in her eyes he couldn't quite put his finger on. John would have known what it was, but John hadn't been there for years.

And that was the problem.

"You can't be here," Sherlock forced out, needing her gone. "You need to leave."

Rosie twitched her lips at him, arms crossed and with a raised eyebrow that made her look so much like her mother it made Sherlock's chest hurt. "That's not going to happen."

Sherlock attempted to pull himself up to his full height in order to tower over the young woman who was slightly shorter than her father. He could tell from her expression he wasn't intimidating her very well.

"You will leave or I will call…"

"My parents?" she interrupted. She ignored Sherlock's flinch and took a step towards him. "Go ahead. I dare you."

Sherlock stepped back from Rosie and she stopped moving. He took that moment to try and read her, but his mind was trapped in a swirling fog he couldn't quite push through. All he knew at that precise moment was that Rosie couldn't be anywhere near him. He was dangerous; he was bad; he'd gotten both her parents killed.

He'd made a vow to protect the young woman standing in front of him, and the closer she was to him, the further away from safety she was.

Rosie had been waiting patiently while he worked through things in his head, and was leaning against her father's old chair when he refocused on her.

"Where's…Molly?" he asked. At Rosie's questioning look, he twitched a hand towards her. "Isn't she supposed to be looking after you? Why has she let you come here?"

"Because I'm an adult and Molly is my godmother, not my keeper or jailer."

"Only because she isn't doing her job properly," Sherlock grumbled under his breath, turning towards the kitchen. He paused for a moment, before turning back to her. "You're an adult? When did that happen?"

She smiled slightly, the same way her Mary did when she thought he was being especially slow. "Yeah. Thanks for noticing. It was last week."

"Many happy returns," Sherlock ground out grudgingly. "Leave."

"Make me."

Sherlock stared at her incredulously. "I will."

"Okay."

He ground his teeth in frustration but didn't make a move towards her. "Get. Out. Now." He even pointed to the door helpfully.

When he didn't make a move towards her, Rosie smile brightened triumphantly, as if he'd answered a question she hadn't asked. She pushed John's chair and held her hands up in surrender. "Okay, okay, I'm going. I just thought I'd introduce myself to my new flatmate before I moved in and freaked him out."

Rosie had a hand on the doorknob when her words registered in his brain. "What?" Sherlock asked, whirling around to look at her.

She looked over at him with a stubborn set to her eyes that reminded Sherlock of her father. "You heard me. I'll be by tomorrow with Greg to start cleaning up the room upstairs."

"No," Sherlock said firmly.

"Tomorrow at about noon, I think. Greg is _not_ a morning person unless he has to be. I'm sure you remember. Plus, he was oddly reluctant to come with me tomorrow." She raised an eyebrow at him. "Wonder why that would be."

Sherlock glared at her. "Because I don't take kindly to unwelcome visitors, _Rosamund_."

She smiled brightly as she left the flat. "Good thing I'm not a visitor then, _William_."

He pinched his lips together angrily and moved to watch her skip quickly down the stairs. "What are you then?" he called out, hoping it sounded like a challenge.

Rosie turned at the front door, meeting his stare head on and without fear, trepidation, or any evidence at all that she was put off by him.

"I'm your new flatmate. _And_ your goddaughter."

Rosie waved sweetly and then left the flat calling out a goodbye as she left. Even through the fog that lay over his brain, he noticed she used the door knocker to shut the door.

He sighed and slammed the door shut, hard, hoping it would annoy Mrs. Hudson and that Rosie would be able to hear it and his anger from the street.

When he turned around, the hallucination of John that he was used to seeing was leaning up against the same spot Rosie had been moments before. "You could have just taken her arm and forced her to leave," the hallucination said.

Sherlock frowned at the grey-haired man in front of him, wearing a tan jumper and jeans that looked eerily similar to what Rosie had been wearing.

"Piss off," Sherlock muttered, slamming doors and obstacles in his way as he moved towards his bedroom. When he slammed that door shut too, he glared at the hallucination of John leaning against the far wall.

Both he and his hallucination knew he hadn't physically escorted her out of the flat by her arm because they both knew he'd never lay a hand on John and Mary Watson's daughter.

He flopped face first onto his bed, disturbing dust and a large pile of junk as he did.

"You like her," John said from his position in the corner of his room.

"Shut up," Sherlock grumbled, voice muffled by the pillow.

As John's laugh followed him down into a hazy sleep, Sherlock's dreams were filled with blonde hair and grey-blue eyes.

Somewhere, deep in the dark corners of his mind palace, a soft, weak light began to glow.


	2. Chapter 2

2)

 _The first thing you are going to have to do, before even beginning to deal with Sherlock, is clean the flat._

 _Trust me. It will be gross._

 _Be advised, there might be what Sherlock calls "experiments" in various nooks and crannies. This could include but is not limited to body parts in the refrigerator (yes, you read that correctly. No, he isn't a serial killer or cannibal), mould in the bathroom, and/or dangerous chemicals in the cupboards (no, they will not be labeled properly. Double check before eating or cleaning with anything, including things that you bought yourself). Be very careful. If necessary, get Greg to send one of the teams of people who clean up after crime scenes._

 _A few notes about cleaning the flat:_

 _1) Don't worry about the dust unless it is unhygienic to a truly horrifying level. Sherlock likes the dust. He'll wax on about the elegance of it, but really it lets him know who has been in the flat and what they have done. It's saved our skins several times._

 _2) The human skull on the mantel belongs there. I don't know who he was before he sat there, but that's where he belongs now. He's part of the flat, so don't move him or get rid of him. Keep in mind, Sherlock will try to hide things under the skull. For example, a pack of cigarettes will fit neatly under it._

 _3) There is a yellow smiley face on the far wall. Do not take it off. Ignore the bullet holes._

 _4) The headphones belong on the animal skull on the wall between the two windows._

 _The upstairs bedroom used to be mine, so it's yours now. I don't know what kind of condition it will be in so approach with caution._

 _Sherlock is going to resist you and will probably behave like he is under personal attack. You are going to need to pick your battles. Try to keep his piles of stuff in semi-pile-like order and try not to move the furniture around too much. His clutter really isn't clutter; there is a method to his madness. A lot of it could be crime scene photos, detailed descriptions of dismemberments, and medical/criminal theories._

 _I hope you have a strong stomach._

 _Cleaning the flat is going to be one of the first major obstacles you'll have to hurdle. I know it won't seem like it since he'll probably still be trying to decide what to do with your presence and won't be as aggressive with you as he will be later when he gets his bearings. However, he will be nasty and rude to anyone else you bring by, so maybe make apologies beforehand._

 _Getting things cleaned and organized is the first step you'll need to take, not only because the flat will need it, but because hopefully you can get him to take clients again at some point, and they aren't going to be able to see him in a flat that needs to be condemned._

 _Also, despite what he's going to tell you, his mind works better when things are in some sense of order. It helps him focus, helps to put puzzle pieces together, and when he focuses and puzzles he saves lives and brings justice to those who have nowhere else to go. I know how cheesy it sounds, but it's true._

 _So, the first battle to win in the war for Sherlock's life is getting the flat cleaned._

 _Good luck, Love. You'll need it._

* * *

Sherlock blinked sleep crusted eyes open, staring at the grimy bedspread in confusion before he remembered what had happened the day before. He rolled over with a groan, a migraine forming behind his eyeballs, reminding him it had been a while since he'd gone out to get anything stronger than cigarettes.

He'd have to remedy that soon.

The hallucination of John was nowhere to be seen and even as the pain of loss hit Sherlock's chest before he brutally brushed it off, he was grateful.

Sherlock was halfheartedly trying to convince himself that he should get up when he heard the voices and movement in the main living space of the flat. After a moment, he heard one soft voice he'd recognize anywhere, even after only hearing it once the day before, and forced himself to his feet. Sherlock stumbled towards his bedroom door and at the last moment, he pulled on a dingy dressing gown and grungy sleep pants in a brief fit of modesty, before he made his way into the flat.

Sitting on a tall stool in the middle of the living room was Rosie, a cup of tea on the side table in next to her. Wearing worn jeans and a thin tee shirt, she was pointing and speaking to the other people in the room as they moved around.

Cleaning.

Greg was the first to notice Sherlock standing at the end of the hallway in shock as he watched the strangers disinfecting his flat. He was sitting in what used to be the "client chair", one leg thrust out into the middle of the floor looking at Sherlock warily.

When Sherlock met his gaze, Greg nodded at him slightly and sat up straighter in the chair.

Rosie caught the nod out of the corner of her eye and glanced over her shoulder at him. She smiled brightly, but with the same hint of something in her eyes that Sherlock couldn't put his finger on. Then, she whipped her braid behind her shoulder as she turned to look at what one of the figures in blue cleaning suits brought her.

It was his skull.

"Put that down," Sherlock ground out as he found his voice.

The cleaner looked up in surprise at the tone, and then glanced over to Rosie. Rosie just held her hand out and the cleaner dropped it into her hand.

"Put that down," Sherlock said again.

Rosie nodded. "Okay."

Jumping down from the stool, she walked past Sherlock, dodged his attempt to take the skull from her, and put it gently on the center of the mantel. While Sherlock was staring at her, she tilted her head at it, and then slid it over to the left-hand corner, pointing the face out to the room.

"There," she said with a gentle smile, looking at Sherlock. "Now he can see the room again instead of being hidden behind the couch."

Sherlock just narrowed his eyes at her, willing to make his brain to work to figure out what her motives were. The migraine pulsed angrily as he tried, and he growled in frustration as he stomped off towards the kitchen.

The kitchen was full of people too, and Sherlock turned back to Rosie and Greg. Greg hadn't moved, but Rosie was back on her stool, looking like a queen as she surveyed her kingdom and subjects, directing them to where things belonged, offering suggestions as to where things should go and making decisions as to what was trash and what wasn't.

Sherlock watched the people moving around his flat for a long moment before he couldn't handle it anymore and slammed his open palm hard onto the wall. Everyone stopped moving and turned to look at him at the noise.

"Get out of my flat," he ground out dangerously. The young woman next to him flinched slightly and Greg finally pushed himself to his feet, moving to stand defensively next to Rosie.

Rosie just pinched her lips together in a displeased motion before she turned back to the man in front of her and directed him to put the headphones he was holding onto the animal skull hanging between the two windows overlooking the living area. Taking her lead, the other people began cautiously cleaning again.

Greg watched Sherlock from his position next to Rosie. "You should be thanking Rosie for getting these people to come in here to sift through this toxic waste dump you call a flat."

Sherlock glared at Greg, pleased to see he remembered their last encounter when he swallowed nervously. "Get these people out of my flat. Now."

Greg shook his head. "You'll have to talk to Rosie about that."

Sherlock pointed a long, thin finger at Rosie. "So, all these people are taking orders from her?"

At Greg's nod, Sherlock began to stomp over to Rosie but stopped when he saw the cleaner heading towards his bedroom.

"Stop," he growled dangerously at the woman. She stopped immediately, looking to Rosie for support.

Sherlock didn't wait for Rosie to say anything, he just began stalking towards the cleaner. When a hand landed on his arm before he reached the woman, Sherlock decided he'd had enough. With no indication of what he was about to do, he slipped under the hand, wrenched the arm behind his back, kicked a knee out, and slammed the person into the floor.

"Sherlock Holmes!" Rosie roared from her stool.

Sherlock pressed the head into the dingy carpet, noting distantly that it was Greg as he watched Rosie march over to him without any fear. The brief realization that she wasn't afraid of him flickered through his mind, making him push Greg's head into the ground harder in frustration. Everything would be easier if she was scared of him. Or angry. Or something other than whatever it was she was.

"Release him," Rosie ordered, doing a damn good impression of her father's "Captain Watson" voice. His mind vaguely registered that fact as interesting, especially since she shouldn't have been able to remember it. Just beyond Sherlock's visual of Rosie, John flickered into existence, looking tired and disappointed.

Against his will, Sherlock responded to that voice with a growl and he reluctantly pushed himself away from Greg, taking in the new grey hairs and watching how he seemed stiffer than he once was as he pushed himself painfully to his feet.

Sherlock turned to look at the furious young woman in front of him, feeling a twinge of guilt at her expression. He clamped down ruthlessly on the impulse to apologize and pointed his finger in her face.

"Get these people out of my flat."

Rosie put both hands on her hips, staring up at his towering figure. Her blue eyes were determined. "First off, no. It's disgusting and needs to be cleaned. Secondly," she turned to face the cleaner who had been watching the events unfold with one hand over her mouth and wide eyes. "I already said that Sherlock's room is off limits. If he says we can clean in there, fine, but until he gives us that permission, all of you will give that room at the end of the hall a wide berth. Is that clear?"

Sherlock just watched her, stunned, and took a step backward when she turned to point a finger at him. "And thirdly, Sherlock, we do not treat people this way. I know you've been basically cut off from society for the last seventeen years and you're a sociopath, but you do know how to behave. So, if you are physically incapable of being polite, be civil or go to your room."

Sherlock opened his mouth to tell her where she could put her orders when she turned to look at Greg. "Greg, thanks for helping me out today, I appreciate it. I totally owe you lunch or dinner now. But I think it's best if you take off. I've got things covered here."

Greg rubbed his shoulder absently, giving Sherlock an angry look before he turned his attention back to Rosie. "I'm not sure that's such a good idea."

"I know," she said soothingly. "But I don't think I'm in any danger here. Do you?"

When Greg didn't answer, she gently put a hand on his shoulder and began guiding him to the front door, making promises to see him the next day for lunch. Sherlock watched for a moment, shocked into silence before he realized the cleaners had continued. With a dramatic flourish of his dressing gown, he stomped off to the bathroom and slammed the door shut with a frustrated yell. After he turned around, he groaned in frustration, leaned against the door, and slid to the ground.

They'd cleaned the bathroom too.

* * *

Judging from the stiffness in his knees, it was some time later when the flat's silence suddenly registered in Sherlock's sluggish mind. He pushed himself up to his feet, used the facilities, and then gingerly moved into the main room.

The people Rosie had brought with her were nowhere to be seen, and the flat was almost silent.

And clean.

On further inspection, it looked like Rosie had made them keep things pretty much where they were, although things were stacked neater so piles of his clutter didn't look ready to fall where they stood. The dust had been cleaned, but not well, and Sherlock found himself relaxing slightly at the sight of it. Dust was one of the biggest indicators of what had or had not been disturbed recently. It had always been a valuable tool.

A soft noise from John's room on the third floor made Sherlock abandon his inspection of the flat and look up at the ceiling. He could track the small, quiet feet as they moved around carefully, and he immediately knew who was there.

Taking the steps two at a time, Sherlock was on the landing and standing in the doorway in moments, watching Rosie hang up clothes neatly in the wardrobe from a duffel bag on the freshly made bed. He was about to say something when he noticed the wedding photo of John, Mary, and himself on the side table next to the bed.

Pulling his gaze from the photo, he turned his attention back to Rosie, noting the several boxes still taped shut and waiting for her to unpack.

"What are you doing?" he managed to get out.

Rosie didn't even flinch, having heard his footsteps on the stairwell. "Unpacking my stuff," she said matter-of-factly as she hung up another pair of jeans in the wardrobe and reached for another hanger. She glanced at him out of the corner of her eye and then turned to face him.

After a long moment of silence, Rosie gestured to the chair next to the door. "You can sit down, you know. I'm not going to bite."

Sherlock glanced at the chair but remained standing in the doorway, turning his attention back to Rosie. "Why are you unpacking your stuff?"

Rosie twitched her lips at him that almost precipitated a smile. "Because I'm moving in here," she said slowly as if talking to a small child. "We discussed this yesterday."

Sherlock glared at her. "I don't recall that we discussed anything. I seem to recall you deciding you could just waltz in here, and me telling you to leave."

Rosie raised an eyebrow at him. "Are you telling me to leave?"

"Yes."

With a smile, she planted herself firmly in the middle of the room, one hand on her hip, and nodded. "Okay. Step inside this room and make me."

Sherlock pinched his lips shut and glared at her as he clenched his long thin fingers into a fist. Rosie glanced down at his fist, unconcerned, and then back to his face. She took a couple of steps closer to him, still out of arms reach, but close enough he'd only have to take one step to reach her.

"Get out," he ground out one more time, already knowing the good it would do.

"It's just one step," she cajoled. "One step inside this room and you could easily cart me out to the street. I saw what you did to Greg. Little old me shouldn't be a problem at all."

Behind Rosie, John materialized, hands in his pockets and looking at Rosie with pride. "She's a stubborn little brat, isn't she?" With a grin at Sherlock, he leaned against the far wall, transparent in the light shining through the windows. "Reminds me of her mother. No one could make her do anything she didn't want to do either."

Rosie noticed him glanced over her shoulder, and she turned to look. Knowing she wouldn't see anything there, Sherlock took advantage of her distraction and stomped back down the stairwell.

He hadn't stepped into that room since long before John's death, and he didn't intend to do so now. Not even to remove an eighteen-year-old girl who was too stubborn for her own good.

She'd see soon enough that being around Sherlock was hazardous to her health. He could wait her out, just like everyone else, find her pressure point and push on it hard enough that Rosie left on her own.

In the end, everyone always left.

Walking down the stairs, Sherlock felt the cement and steel he'd poured over the room designated to the Watsons in his mind palace begin to rust and crack. Unbidden, the small part of Sherlock that that hated the silence of being alone peeked out from behind the damage, pleading for Sherlock to go back up the stairs into John's room and clutch the last remaining reminder of his best friend tightly enough that he'd never be alone again.

He couldn't do that though, and Sherlock ruthlessly shoved that small part of him back into the darkened room where it belonged and began attempting to repair the damage. If anything got out of that room, he'd begin to care again. If he began to care again, he knew it wouldn't take much before he reached out to Rosie like it seemed she wanted him to.

Sherlock knew that was out of the question. It had been proved, several times, that anyone he reached out to ended up dead. Sherlock had failed to keep her parents safe, and he had no intention of failing with Rosie.

If he didn't get attached or let himself care, it would be easier when he was finally successful in getting her to leave. It wouldn't break what was left of his heart when he finally got John Watson's daughter to safety.

Stomping back down to his room, he paused as he noticed his violin case leaning against the wall under the window, a small stack of sheet music propped neatly on the music stand. He saw his skull staring out into the room, and someone had cleaned the wall so that the smiley face staring back at him was visible. On the kitchen table, his lab equipment had been cleaned and now stood shining under the kitchen lights.

Even the two chairs next to the fireplace were back where they belonged, dust free and comfortable looking as if waiting for their owners to return to them.

Things were different, but he could see that Rosie had kept things almost as they were when John was alive. Probably with a little help from Greg.

Bastard.

Above him, Sherlock could hear Rosie moving around again, and he leaned one arm against the wall and closed his eyes. After a moment, he glanced up at the ceiling one last time before shaking his head and moving towards his room, vague, half-formed ideas on how to get rid of her crossing his exhausted mind.

Sherlock just hoped that Rosie would not turn out to be as luminous as her father had been. He had survived turning off the lights once, but if Rosie managed to turn the lights back on, Sherlock knew it would kill him when he had to turn them off again.

From the end of the hallway, John frowned disapprovingly at the knowledge that the thought of dying didn't really upset Sherlock in the way it should.

Sherlock slammed the door shut in his face. John was dead anyway; he didn't really get a say in the matter.


	3. Chapter 3

_3)_

"I play the violin when I'm thinking, and sometimes I don't talk for days on end. Would that bother you? Potential flatmates should know the worst about each other." _Those were some of the first words Sherlock ever said to me. Let me tell you, those are_ not _the worst things about Sherlock._

 _Sherlock has no comprehension when it comes to social niceties, zero problem breaking into places he shouldn't be, thinks stalking is an acceptable manner of acquiring information, and judges the severity of a problem by the number of nicotine patches he has on his arm (do not let him use more than four. I don't care what the problem is). He runs headfirst into dangerous situations without considering the effect it would have on the people who care about him, deletes any text that begins with "Hi", has no consideration for personal space, and doesn't think there is anything wrong with giving people chemicals and compounds to see what it does to them (be careful when taking food or drink from him). On top of everything, there are loud and noxious experiments at three in the morning, gunshots to the wall when he's bored, and he will confiscate any of your things for his personal use just because he is too lazy to get up and locate his own (keep an eye on any computers or cell phones you might have left unsupervised in his presence. Passwords don't do shit to keep him out)._

 _With all that, Sherlock is a good man, no matter what he wants the world to think. He's brave, honest, loyal to a fault, protective, and intelligent. He is the wisest man and the most human human being that I have ever known. I can list his faults, and then some, but the truth is, I wouldn't change a thing about Sherlock. His faults are what make him who he is, and I'd bet on Sherlock every time, no matter the odds._

 _Sherlock is also the most compassionate and empathetic person I've ever known._

 _Sherlock told me once that being alone is what protects him. At the time, I was so angry with him, I didn't put together his meaning until years later. The truth is, Sherlock_ feels _, deeper and more intently than anyone I have ever met. The sociopathic mask he hides behind is his shield that keeps him from getting hurt; just as he feels love and compassion more than a normal person, so too are the feelings of loss, betrayal, and grief magnified._

 _I obviously don't know the circumstances surrounding my death, but I can guarantee you Sherlock is going to think it's his fault; he's going to legitimately think that he should have been smarter, faster, or never even allowed us to become friends. He'll take responsibility for it because that's what he does; he cares so strongly about the people he allows to be friends, that he can't understand why he can't keep the world from hurting us. Sherlock knows he's exceptional and feels he should be able to use that to keep everyone safe. What he doesn't understand is that he is also a fallible and fragile human like the rest of us mortals._

 _Know this, Rosie: I make my own choices, and I chose to follow Sherlock into the jaws of danger. My death was not his fault. Your mother's death was not his fault. We had the time of our lives with him. No one can ever convince me it wasn't worth it._

 _This brings me to you. When your mother and I were married, Sherlock stood up at the end of the night and made a vow. He looked your mother and me in the eye, and in front of all the guests promised he would always be there for us. For the_ three _of us._

 _Now, you are the only one left, and he will be trying his damndest to keep you safe. In his mind, it will be his fault that you won't have parents and keeping you as far away from him as possible is the only way to make sure you are safe, protected, and loved. U_ _nderstand that Sherlock did everything he could to send me back to you._

 _When Sherlock shoves you away, and he_ will, _remember he's doing it to protect you. Stand your ground, weather the storm, and remind him that Watsons never leave a man behind._

* * *

Sherlock was lying quietly on the couch, fingers steepled under his chin when Rosie walked in the front door. He made no move to acknowledge her presence as she gave him a soft "Hey" on her way past him. His passivity made her pause and look at him suspiciously for a moment, but he knew she was tired when she didn't focus on him long before shrugging and kicking off her shoes, taking off her green canvas jacket, and dropping her book bag in John's chair on her way into the kitchen.

Sherlock tracked her movements by sound as she made tea. He heard the water running as she filled up the kettle and the soft 'snick' of the kettle as it is turned on. The creak of the cupboard was next as she got her mug and tea from the top cupboard, then the soft click as she set the items down on the counter. Sherlock could hear the water starting to boil in the kettle, and then smiled to himself as he heard her feet tapping on the linoleum on the way to get milk from the refrigerator.

"Is this necessary?" John asked from where he sat on the table across the room watching Rosie move around the kitchen. Sherlock could hear the sound of her feet pause as her cell phone pinged quietly. "I hated finding dismembered body parts in the refrigerator, and I was a doctor! She's just a kid. This might be the thing that sets her off and makes her leave."

"Good," Sherlock muttered to the hallucination, noting it was wearing John's black and white striped jumper and date shoes this time.

"Good?" John almost shrieked. "What the hell is wrong with you?"

"A lot," Sherlock muttered as he heard Rosie toss her cell phone on the kitchen table, and the sound of the refrigerator finally opening.

Rosie shrieked and then slammed the door shut. Sherlock grinned to himself.

"All right?" he asked casually as he pushed himself to a sitting position, arranging his dressing gown over sweats and a tee shirt. From his position, he couldn't see Rosie, but his mind was doing an excellent job of imagining her disgusted and horrified face as she saw the dismembered head sitting in the refrigerator. If she opened it again she would see several fingers in the milk and a decomposing liver in the vegetable drawer where she was keeping the tomatoes she wanted to use for dinner.

Two audible deep breaths, quiet muttering and one grunt later as she wrenched the refrigerator door open back open, a furious and fuming Rosie stomped around the corner.

And threw the dismembered head at him with all the force she could muster. It hit him in the chest and bounced off onto the floor.

Sherlock jerked back from it in surprise and stared as the head rolled across the floor. Up to this point, Rosie had responded to all of Sherlock's attempts to force her to leave with annoyance, reluctant acceptance, a sort of exasperated disregard, and once full out laughter.

She hadn't thrown anything at him yet.

Sherlock stood up, blinking at her as Rosie stood in the doorway, hands on her hips, glaring at him.

"What the hell wrong with you?" she shrieked, sounding just like John in the corner who hadn't stopped laughing since the head had been launched at him seconds before. At her question, he started laughing harder.

Faintly he thought he could hear Mary's voice whisper "that's my girl".

"What is wrong with me?" he finally asked. "You're the one who just threw a head at me."

Rosie rolled her eyes. "Please. That can't be the first time that's happened." When Sherlock raised an irritated eyebrow at her and shoved his hands into his sweatpants pockets. Rosie's eyes widened. "Oh my God, it is. What? People just let you do whatever you want, don't they? I mean Molly warned me, but this is ridiculous! It's like no one has ever told you you're being a complete and utter _wanker!_ "

Sherlock shrugged, pleased with the angry response he was getting. He ignored John's disapproving glare. "It's my flat, I can do what I want there. If you don't like it, there's the door."

Rosie gave him a sort of frustrated growl and turned back to the kitchen. Sherlock sighed and turned to investigate the head on the floor, wrinkling his nose at the fluid seeping into the carpet. While his attention was elsewhere, a finger hit him in the head. Sherlock jerked up, managed to dodge the thumb, but then a middle finger him just below his eye.

"Ow!" he complained.

Rosie raised her eyebrows at him. "Ow? Really? Ow?" Another finger flew at his head, and Sherlock dodged it, desperately hoping that the liver would not be next. That would splatter if it hit anything with any measure of force, and Sherlock was not looking forward to the smell of formaldehyde invading the flat.

Sherlock frowned at Rosie as he wiped the residue off his face the finger had left with his dressing gown. "I was measuring the rate of saliva…"

"No," Rosie interrupted. "You were not measuring saliva, or blood coagulation, or the effects of acid on the human face. You were trying to frighten me and get me to leave." She sighed, grimacing at the fluid on her hands and turned back to the kitchen. A moment later and Sherlock heard the water in the sink running.

Sherlock had tried shooting the wall, keeping her up at all hours of the night, deliberately messing up anything she tried to clean, frightened the neighbor who had come by to say and had spent the day before insulting her while she worked on her computer. He'd tried deducing her, but it had made his brain pulse angrily and the small room in the back of his mind palace groan against the strain so he'd stopped.

Rosie had basically ignored his attempts to get her to leave. Her tantrum about the body parts in the refrigerator had been unexpected, but welcome. She was angry, annoyed, and tired.

Sherlock knew exactly what he needed to do to get her to leave once and for all.

Stepping over the head and fingers that littered the living room floor, he leaned casually against the doorframe as he watched her carefully wash her hands. He waited until she turned around, looking at him quizzically before he said, "I killed your parents."

Rosie flinched like he'd slapped her. He could hear John behind him growl his name in warning and Mary's order to 'don't!' but he had to push forward.

For Rosie's sake.

"I killed them. I put your mother deliberately in front of a bullet because she was an insipid and insufferable presence I was forced to deal with. She was an excellent shield. Really, it was the only thing she was ever good for."

Rosie swallowed hard, eyes pinching at the corner in pain. She gripped the counter behind her with both hands, her knuckles turning white. "That's not true," she whispered.

"It is," Sherlock said, struggling to put on a mask of indifference. John would have seen through it, but Rosie wasn't John. "Honestly though, I was most relieved when your father drowned. He'd become impossible to deal with after your mother died. Really, the melancholy and the meaningless drivel he'd mumble to himself was so…messy. And irritating. I could feel my IQ dropping the longer I listened to him. He never was the most luminous of people, but then his wife was killed and he became even duller than he already was."

Rosie licked her lips and shook her head. "I know what you're doing. Stop."

"Telling the truth?" Sherlock interrupted. "The truth is, I had a choice. I could have saved my sister or I could have saved John. I chose my criminally insane sister, without blinking. I let your father drown because then I wouldn't have to listen to any of his meaningless drivel anymore."

Rosie sniffed slightly, shook her head, and then walked out of the room, slipping her feet into her shoes and reaching for her jacket. She had moved towards her bookbag on the chair next to him when he hammered home the last nail.

"You thought I cared about your parents? Honestly, the only thing more painful than dealing with such _boring_ people is when they constantly foisted their infant daughter on me. Really, you never wondered why I never contacted you at all? I knew you'd be dull, ordinary, and _obvious_ , just like your sniveling parents. You think because you're my goddaughter it makes you special? You're a waste of air and potential. Your parents were the same, and it's clear that you are just like them. _Replaceable._ "

Rosie blinked at him once, before turning on her heel and marching out the door, head held high and back ram rod straight. Sherlock listened to her soft footsteps on the stairs and then the sound of the front door closing quietly.

Sherlock swallowed as he went to the window and watched her walk slowly up the street until she managed to hail a cab and was whisked away into the early evening light. Sherlock shook his head. It'd have been easier if she had ranted and raved at him or even slammed the door. He swallowed once more and turned to pick up body pieces off the floor before the room started to stink.

"Right, well done," John said from his perch across the room. "What if she doesn't come back?"

Sherlock ignored him as he used a dish towel to pick up the fingers and head. He could feel John watching him as he moved to dump them into the sink. The milk had been completely emptied in order for Rosie to get the fingers out of it, and it pooled thickly in the drain, blocked by another finger.

John was silent for a long moment, and Sherlock finally glanced over to see him staring thoughtfully at him. "You don't want her to go."

"That's irrelevant. She's safer when she's not around me." Sherlock tilted his head at John. "I did think that being your and Mary's daughter that it would take more than a month to get rid of her."

"You still don't want her to leave," John insisted. "She might be safer without you, but you've gotten used to the noise and the presence of another person. Especially another person you care about as much as you care about Rosie."

Sherlock glared at John. "When it comes to Rosie, what I want doesn't matter. Only keeping her safe matters. I will peel the flesh off my fingers before I let her put herself in harm's way."

John's quiet voice followed him down the hallway to his bedroom. "Doesn't she deserve that choice?"

Sherlock slammed the door in his face.

* * *

Rosie didn't return to the flat for four days.

On the second day, Sherlock sucked in a deep breath and called Scotland Yard to see if Rosie had turned up recently. Greg didn't answer his query; instead, he yelled at him for ten minutes about his behavior towards Rosie and then hung up on him.

Molly didn't even answer her phone. Sherlock supposed that meant they had at least seen Rosie in recent memory as they appeared to be well informed as to what Sherlock had done.

By the third day, Sherlock could feel the walls surrounding his broken heart start to crumble. John had been mysteriously absent from the flat since he'd slammed the door shut in his face, no doubt furious over how his daughter had been treated, and the loneliness and despair had crashed full force into Sherlock, reminding him just how well he operated on his own.

By the middle of the fourth day, Sherlock was sitting on the edge of the bed trying to decide if getting Mycroft to track Rosie's phone would do more harm than good to the cracked walls of his mind palace when he finally heard soft footsteps on the hardwood floor just outside the living area of the flat.

Sherlock pushed himself to his feet and moved to stand by the edge of the hallway. As Rosie came in, he noticed she had a new book bag and was wearing different clothes than when she'd left. Wearing black leggings and a long grey knit dress, she looked tired but unharmed. Sherlock let a small moment of relief hit him as he recognized she was okay; he had been sure she'd been fine and gone back to Molly's, but Molly's refusal to speak to him and Greg's angry ranting had not been enough to satisfy the lack of data he faced at Rosie's disappearance.

Rosie glanced up at him neutrally as she dropped a box of Chinese food on the table. "Dim Sum," she said by way of greeting. She tossed her shoes into their normal place and tossed her bag on top of the one she'd left there the night she'd left. Sherlock hadn't touched it.

Keeping her distance, Rosie looked at him critically, and Sherlock let her stare at him. She pulled the hair tie from her hair, allowing blonde hair to fall down her back and ran her fingers lightly through it in a nervous motion Sherlock remembered her father doing. Finally, she took what looked like a forced step towards him and pointed to the food on the table. "Eat."

Sherlock glanced at the food, then back at Rosie. "What are you doing here?" he whispered.

Rosie shrugged her shoulder. "Feeding you. You look like you haven't eaten since I've left."

Sherlock was silent, just continuing to stare at her. Rosie sighed, moved towards the stairs, and then turned back to him, surprising him with the determination in her gaze. "Look, I get that you are trying to protect me. I get that you think some monster from your past is going to rise up the second you allow yourself to show affection for me and murder me in my bed. I even get that you think you killed my parents."

Sherlock opened his mouth to protest but Rosie just steamrolled over him. "Here's what you don't get: You don't get that I'm not some damsel in distress who needs a dark knight on a white horse to save her from the dragons in the world. I'm not going to run from your eccentricities, I can deal with your attitude, and I most certainly can deal with your antisocial, sociopathic tendencies."

Sherlock just stared at her, unsure of what to say. She shook her head. "You forget that I am an adult who can make her own choices. Just like my parents made their choices. You've pushed away anyone who cares about you and convinced yourself that you are better alone. That alone protects you. You think that if you are enough of an arsehole you can push me away the same way. You're wrong."

Rosie was on a roll, and Sherlock watched warily as she moved to stand firmly in front of him, unable to move from the gale force that was his goddaughter.

The realization hit him like a bullet to the chest: Rosie was fighting _for_ him in the same stubborn way her parents had fought for him all those years ago.

"I know you forget this, so I'm going to keep saying this until it sinks into that big brain of yours. You are family. You are my family. Family means forever and forever means that no one gets left behind. So, stop being a dickhead, man up, and accept that I'm here for the long run. You've been alone for far too long and I'm not putting up with it anymore."

Sherlock shook his head, trying not to look at Rosie as he said, "You wouldn't be saying any of this, wouldn't be so insistent on calling me family if you knew what I did to your parents. I may not have pulled the trigger, but what happened to them was my fault."

"What makes you think I _don't_ know what happened to them?" Rosie's soft voice came out. Sherlock jerked as she put a hand on his arm, but she held on, fingers gentle and unyielding. Sherlock looked up cautiously at Rosie as she firmly held his gaze. "Their deaths are public record, and I am a damn good researcher. I've also read my dad's blog and I've seen my mother's notes on the various cases the three of you worked together on."

"You still don't know the details." Sherlock protested. "Public record only gets you so far."

"You're right, and one day you and I will sit down and you will tell me the whole story. But what I do know for one hundred percent certainty is that their deaths were not your fault." Rosie hitched a shoulder. "Sometimes you can't save everyone. And it sucks. Failure is part of life. The failures and losses we endure remind us to do better the next time. What's not acceptable is forgetting the people that are still here, especially when you promised their parents you'd look after them."

Sherlock flinched and pulled out of her grasp. "I am looking after you. Keeping you away from me, that's looking after you. I don't want what happened to your parents happen to you."

"Their deaths were not your fault, Sherlock," Rosie said firmly leaning against John's chair. "Sometimes bad things just happen, and there isn't anything you can do about it, no matter how exceptional or brilliant you are."

"And that's supposed to make it better?"

Rosie shook her head. "No. It just…is what it is. We take what we have, we learn from it, and we deal with it." She gestured to Sherlock. "But what you're doing, pushing away your friends and attacking me because you think you can protect us better if you don't let yourself care about us is not dealing with it. I hate to tell you this, but _you_ are the one hurting me more than anything you think you might or might not be protecting me from."

Sherlock looked up at her for a moment before turning to face the wall, trying to keep the wall in his mind palace from crumbling under the weight of Rosie's admission that he was hurting her. "One day I'm going to let you down. One day I won't be able to protect you if you stay close, and that could get you killed. I can't have that."

"What about me?" Rosie asked quietly, moving so he was forced to look at her. "Don't I get a say?" When Sherlock finally met her gaze, she smiled gently at him. "I want you to listen carefully to me. _You are not responsible for every bad thing that happens in the world_. Or to me. We're all only human after all."

"Even you?" he asked quietly, remembering telling the same thing to her father almost twenty years before.

Rosie smiled. "No. Even you."

Under the brilliance of Rosie's forgiving smile, the wall surrounding what was left of Sherlock's heart crumbled into dust and cautiously pushed itself into the light.


End file.
